1. Field of the Invention
The present invention generally concerns the (i) membrane housings, (ii) automatic shut-off valves, (iii) check valves, and (iv) reverse osmosis membrane cartridges, as are all within cartridge-type reverse osmosis systems that are primarily used in water purification.
The present invention particularly concerns improvements to a reverse osmosis membrane housing in order that it should integrally incorporate (i) both a check valve of a new, wide-area, construction and also a shut-off valve, and (ii) an optional pressure gauge, and in order that it should accommodate a new (iii) full-volume high-flow membrane cartridge, all the while that it is (iv) quickly and easily connected within a reverse osmosis system by a (net) reduced number of plumbed connections.
2. Description of the Prior Art
2.1 General Status of Prior Art Reverse Osmosis System Components, Specifically Including the Reverse Osmosis Membrane Housing
The present invention will be seen to be embodied in a reverse osmosis membrane housing. Perhaps because these housings are presently (circa 1997) competitively produced by many sources--and have thus often been manufactured with such extreme economies of design, material and workmanship as have led to premature failure by bursting, and the subsequent demise of many manufacturers--the reverse osmosis industry has not heretofore shown much progress in perfecting this part. Although many dozens of different housing designs all accommodating the same universally-sized R.O. membrane cartridges exist and, indeed, have been collected for study by the inventor, these housings look, and function, very much the same. They are mostly simple cylindrical containers with screw caps that serve to house R.O. membrane cartridges, and to which plumbed connections may be made.
Meanwhile, another component of a reverse osmosis system--an automatic shut-off valve that prevents feed water from being fed to the R.O. membrane when no more product, purified, water is presently required (such as occurs, most commonly, when a storage tank of purified water is full)--has existed apart from the reverse osmosis membrane housing. The automatic shut-off valve requires four (4) plumbed connections.
Yet another valve--a check valve that prevents that the reverse osmosis membrane should be ruptured by an abnormal back-pressure in the product, purified, water line--has previously been incorporated within a reverse osmosis membrane housing.
Other R.O. system components--such as an occasional input line pressure gauge by which the correct operation or, alternatively, the failure, of the R.O. cartridge may be assessed--have also existed apart from the reverse osmosis membrane housing. They have required their own plumbed connections, normally two (2) such connections for an in-line pressure gauge.
Finally, because every manufacturer's R.O. membrane housing unit has needed to accommodate the vast supply of universal R.O. membrane cartridges having a standard form, it has been easy to push responsibility for the perpetually-desired higher purification rates onto the membrane manufacturers, and to ignore any possible complicity of the housing in limiting purification rates.
It is the premise of the present invention that major improvements can be realized in the reverse osmosis membrane housing of a reverse osmosis system. These improvements will be seen to concern (i) an higher degree of integration, reducing net plumbing requirements for the overall R.O. system (although plumbing requirements to the reverse osmosis membrane housing itself will be seen to be slightly increased), (ii) a new, larger, better-performing, check valve, (iii) accommodation of new and larger, high-flow-rate R.O. membrane cartridges in the same housing that otherwise fits universal standard cartridges, (iv) optional integration of useful gauges with the reverse osmosis membrane housing, and (v) easier, faster, hook-up.
2.1 Specific Prior Art Reverse Osmosis System Components, Including the Reverse Osmosis Membrane Housing
The reverse osmosis membrane housing of the present invention will be seen to incorporate an automatic shut-off valve. A previous shut-off valve for an R.O. system--but not the reverse osmosis membrane housing of the system--that is based on the weight of the purified water is described in U.S. Pat. No. 3,939,074 to Bray for an APPARATUS FOR CONTROL OF A REVERSE OSMOSIS SYSTEM, assigned to Desalination Systems, Inc. (Escondido, Calif.). The Bray system concerns a reverse osmosis system having a tank for storing purified water and a valve in a pipe which introduces feed water into a module containing a semipermeable membrane that produces the purified water. The valve shuts off or turns on introduction of feed water into the module in response to the weight of purified water in the storage tank.
Another automatic valve is shown in U.S. Pat. No. 4,190,537 to Tondreau, et. al. for a WATER STORAGE CONTROL FOR REVERSE OSMOSIS SYSTEM, assigned to Desalination Systems, Inc. (Escondido, Calif.). Therein reverse osmosis system employs a tank for storing permeate under a pressure which is a portion of the pressure of feed water introduced into a pressure resistant container housing a semipermeable membrane cartridge. A control mechanism such as an automatic valve, preferably of the double diaphragm type, located in the line introducing feed water into the pressure resistant container closes to shut off feed water flow when the pressure in the permeate storage tank reaches a first predetermined value, less than the feed water pressure, and re-opens to re-establish feed water flow at a second predetermined pressure lower than the first or shut-off pressure. A constricted passageway device such as a venturi in the pipe or connection between a dispensing device such as a faucet and the permeate storage tank has its throat communicating with the sensing conduit for actuating the feed water control valve. When the dispensing faucet is opened, flow of permeate through the venturi creates an amplified and drastically reduced pressure in the sensing conduit, and applies a servo or magnified actuation force to the valve in the re-open end of its control range.
U.S. Pat. No. 4,705,625 to Hart, Jr. for a REVERSE OSMOSIS WATER PURIFYING SYSTEM concerns a reverse osmosis (R.O.) water purification system that collects and stores pure water at low pressure and dispenses it at high pressure. Impurities left behind when the water passes through a R.O. module are disposed of by two methods: the fast flush method and the slow flush method. In the fast flush method, water entering a R.O. module may take two paths to escape therefrom. The first path constrains it to travel through a semi-permeable membrane in the module which filters out undissolved solids and which restrains the passage of dissolved liquids. The second path allows it to travel through the R.O. module, without passing through the membrane, thereby carrying out those impurities left behind by the water passing through the membrane. The purified water is directed to one side of a compartmented storage tank and the waste water from the module is directed to a control valve. From the control valve, the waste water may be directed through a restriction to a drain or it may be directed to the other compartment of the storage tank where the purified water is held. In the slow flush method, water enters a control valve, travels to the R.O. module, and has two paths of escape therefrom. The first path constrains it to go through the semi-permeable membrane in the R.O. module, and through a check valve to storage or outlet. The second path allows the water to escape through the R.O. module, thereby carrying to a drain the impurities left behind.
U.S. Pat. No. 4,830,744 to Burrows for a REVERSE OSMOSIS ASSEMBLY OPERATING VALVE concerns a single control valve and associated conduits for operating a reverse osmosis assembly that includes a reverse osmosis cartridge, a reservoir that has a movable barrier therein that subdivides the interior into first and second confined spaces of variable volume, and a manually operated purified water dispensing valve, so that as the first confined space approaches a filled condition with purified water, the single control valve throttles the flow of pressurized feed water to the cartridge to minimize the use of feed water in the operation thereof, with the maximum backpressure to which purified water is subjected in discharging from the cartridge being that due to the weight of reject water in the second confined space, and a membrane in the reverse osmosis cartridge being fast-flushed with feed water to remove foreign material therefrom when the purified water dispensing valve is discharging purified water.
U.S. Pat. No. 4,834,873 for a COMBINED REVERSE OSMOSIS UNIT AND WATER INFLOW CONTROL VALVE FOR A WATER PURIFICATION SYSTEM to Burrows concerns an improved reverse osmosis unit for use in a water purification system. The reverse osmosis unit includes an integral control valve for regulating water inflow in response to system demand for purified water. The reverse osmosis unit includes a feed water inlet receiving a supply of ordinary tap water or the like for flow through a reverse osmosis cartridge having a membrane for separating the water inflow into a relatively pure water supply and a reject water supply with impurities concentrated therein. The pure water supply is coupled through a pure outlet port for collection within an appropriate storage vessel to await dispensing through a faucet valve or the like, whereas the reject water supply flows through a reject outlet port for discharge to a drain. When the storage vessel reaches a predetermined or substantially filled condition, the fluid pressure within the storage vessel acts against a control piston to displace the reverse osmosis cartridge and an integrated inflow control valve carried thereby toward a position closing or throttling the incoming feed water flow.
U.S. Pat. No. 4,876,002 to Marshall, et. al. for a REVERSE OSMOSIS WATER PURIFICATION UNIT, assigned to Schlumberger Industries, Inc. (Atlanta, Ga.), concerns a domestic reverse osmosis water purification system. Few parts in the controller valve mechanism reportedly enhance reliability and economic feasibility. All surfaces of the controller valve mechanism in contact with water are non-metallic and are constructed of FDA approved materials. In addition to its normal function of metering the reject water flow, the controller valve mechanism allows the homeowner to easily rinse the reverse osmosis membrane and conserves water by automatically stopping influent water flow when the product storage tank is full.
U.S. Pat. No. 5,002,668 for a HOUSING CONTAINING A PENETRABLE MEMBRANE SEALING AN EVACUATION OUTLET to Spranger, assigned to Gambro Dialysatoren GmbH & Co. KG (Federal Republic of Germany) concerns a diffusion and/or filtration apparatus. The apparatus includes a housing consisting of a cylindrical open-ended main part closed by two end caps and being provided with an inlet and outlet for a first fluid and at least one outlet for a second fluid having a penetrable membrane, said first fluid being adapted to flow through the fibers of a bundle of semipermeable hollow fibers arranged between two end walls within the housing and said second fluid being adapted to be removed from the space outside the fibers through said at least one outlet for the second fluid.
U.S. Pat. No. 5,503,735 to Vinas, et. al. for a MEMBRANE FILTRATION SYSTEM WITH CONTROL VALVES FOR OPTIMIZING FLOW RATES, assigned to Water Factory Systems (Irvine, Calif.), concerns a liquid purification system. In this system water is pumped into a filter cartridge. A reverse osmosis filter membrane in the filter cartridge removes impurities from the water, but not all of the water passes through the membrane. Water passing through the membrane exits the filter cartridge through a first outlet port, and is sent to a storage tank. Water not passing through the filter membrane exits the filter cartridge through a second outlet port. This water then passes through a pressure relief valve. The pressure relief valve can be adjusted to vary the water pressure and flow rates in the system. Some of the water exiting the pressure relief valve passes through a flow restrictor valve and then to drain. The flow restrictor maintains a constant flow rate at variable pressures. In this system, the flow restrictor is operable to maintain the same flow rate through it to drain and through the first filter outlet port. The match of these two flow rates results in a preferred 50% recovery rate of filtered water. Water that does not pass through the flow control restrictor is returned to the pump inlet for recycling through the system. An automatic flush system and various control functions for operation of the system are also discussed.